Difference between revisions of "CCNP TSHOOT Learning Guide/Chapter 4"
From Teknologisk videncenter
m (→Troubleshooting Spanning Tree) |
m (→Example) |
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###Further ties are broken by lowest port ID | ###Further ties are broken by lowest port ID | ||
#Ports that ended up as neither a root port nor a designated port go into [[Spanning_tree_protocol#STP_Port_States|blocking] state | #Ports that ended up as neither a root port nor a designated port go into [[Spanning_tree_protocol#STP_Port_States|blocking] state | ||
+ | ==Analyzing Spanning Tree== | ||
+ | === show spanning-tree === | ||
+ | <source lang=cli> | ||
+ | Heimdal#<input>show spanning-tree vlan 10</input> | ||
+ | MST01 | ||
+ | Spanning tree enabled protocol mstp | ||
+ | Root ID Priority 24577 | ||
+ | Address 0019.e751.0880 | ||
+ | <notice>This bridge is the root</notice> | ||
+ | Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec | ||
+ | |||
+ | Bridge ID Priority 24577 (priority 24576 sys-id-ext 1) | ||
+ | Address 0019.e751.0880 | ||
+ | Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec | ||
+ | |||
+ | Interface Role Sts Cost Prio.Nbr Type | ||
+ | ---------------- ---- --- --------- -------- -------------------------------- | ||
+ | Gi0/1 Desg FWD 20000 128.1 P2p | ||
+ | Gi0/2 Desg FWD 20000 128.2 P2p | ||
+ | Gi0/12 Desg FWD 20000 128.12 P2p | ||
+ | </source> | ||
{{Source cli}} | {{Source cli}} |
Revision as of 10:31, 15 June 2010
Maintaining and troubleshooting Campus Switched Solutions
Contents
VLAN Troubleshooting
Layer 2 reviewing
ARP
- show mac-addresses
SW1#<input>show mac-address-table</input>
Mac Address Table
-------------------------------------------
Vlan Mac Address Type Ports
---- ----------- -------- -----
All 0100.0ccc.cccc STATIC CPU
All 0100.0ccc.cccd STATIC CPU
<notice>...OUTPUT OMITTED...</notice>
1 001b.0cba.4f99 DYNAMIC Gi0/9
1 001b.2a32.2e99 DYNAMIC Gi0/5
1 0021.5a7c.5549 DYNAMIC Gi0/4
1 00a0.d1e6.60b4 DYNAMIC Gi0/22
41 0014.f273.96c0 DYNAMIC Gi0/7
<notice>...OUTPUT OMITTED...</notice>
41 001b.0cb6.9141 DYNAMIC Gi0/7
41 001b.0cba.4fc1 DYNAMIC Gi0/9
41 001b.2a32.2ec1 DYNAMIC Gi0/5
12 001f.297d.3460 DYNAMIC Gi0/2
20 00a0.c543.035d DYNAMIC Gi0/6
22 0003.47ca.d67c DYNAMIC Gi0/7
22 000c.296c.1120 DYNAMIC Gi0/12
24 0016.769f.ff4e DYNAMIC Gi0/8
28 0013.2085.a1fe DYNAMIC Gi0/9
28 0013.2085.c447 DYNAMIC Gi0/9
<notice>...OUTPUT OMITTED...</notice>
Troubleshooting layer 2
- Hardware issues (move cable to good port)
- VLAN configuration.
- Inter-VLAN traffic must be routed
- Trunk configuration
- Same trunkprotocol (DOT1Q,ISL)
- Same Native VLAN
Verifying Layer 2 Forwarding
Often used commands
- show mac-address-table
- show vlan
- show interface trunk
- show interface switchport
- show platform forward interface - Example below
- traceroute mac - Example below
show platform forward interface example
Show how the switch will direct traffic
SW1#<input>show platform forward gigabitEthernet 0/1 vlan 1 0021.5a7c.5549 001b.2a32.2e99</input>
Ingress:
Global Port Number: 1, lpn: 3 Asic Number: 1
Source Vlan Id: Real 1, Mapped 1. L2EncapType 0, L3EncapType 3
Hashes: L2Src 0x00 L2Dst 0x09 L3Src 0x00 L3Dst 0x09
Lookup Key-Used Index-Hit A-Data
Classify 68_0070001B_2A322E99-00_00000021_5A7C5549 00FFC 00000000
InputACL 20_0070001B_2A322E99-00_00000021_5A7C5549 01FF8 01000000
L2LrnMsk FF_03FFFFFF_FFFFFFFF-00_000003FF_00000000
L2Learn 83_00010021_5A7C5549-93_00000401_00000000 01840 00000000
L2FwdMsk FF_03FFFFFF_FFFFFFFF
L2Fwd 83_0001001B_2A322E99 0003E 000000C5
Station Descriptor: F005F001, DestIndex: F005, RewriteIndex: F001
==========================================
Egress: Asic 0, switch 1
Source Vlan Id: Real 1, Mapped 1. L2EncapType 0, L3EncapType 3
portMap 0x4, non-SPAN portMap 0x4
Output Packets:
------------------------------------------
GigabitEthernet0/5 Packet 1
Lookup Key-Used Index-Hit A-Data
OutptACL 30_0070001B_2A322E99-00_00000021_5A7C5549 01FFC 01000000
Port Vlan SrcMac DstMac Cos Dscpv
Gi0/5 0001 0021.5a7c.5549 001b.2a32.2e99
traceroute mac
Did not work out all right.
SW1#<input>traceroute mac 001b.0c5d.42c2 0006.5bc5.2dfb</input>
l2trace error response received : 3 from 192.168.4.22
Layer2 path not through SW2 [192.168.4.22].
Layer2 trace aborted.
Troubleshooting Spanning Tree
Example
insert figure 4-9 on page 112
- Elect a root bridge
- based in lowest BID
- Select a root port on each switch.
- Elect a designated device/port on each network segment
- Based on lowest cost to Root bridge.
- Ties are broken on BID
- Further ties are broken by lowest port ID
- Based on lowest cost to Root bridge.
- Ports that ended up as neither a root port nor a designated port go into [[Spanning_tree_protocol#STP_Port_States|blocking] state
Analyzing Spanning Tree
show spanning-tree
Heimdal#<input>show spanning-tree vlan 10</input>
MST01
Spanning tree enabled protocol mstp
Root ID Priority 24577
Address 0019.e751.0880
<notice>This bridge is the root</notice>
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 24577 (priority 24576 sys-id-ext 1)
Address 0019.e751.0880
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Interface Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Gi0/1 Desg FWD 20000 128.1 P2p
Gi0/2 Desg FWD 20000 128.2 P2p
Gi0/12 Desg FWD 20000 128.12 P2p